Quantitation of and inter/intra-individual variability in major carotenoids of mature human milk

Abstract

The quantitation of carotenoids from milk has been technically challenging due to the small quantities present, insolubility and instability of the carotenoids, and significant inter- and intra-individual variation. Here we report methods for extraction and quantitation by high pressure liquid chromatography of the major carotenoids, β-Cryptoxanthin, lycopene, α-carotene, and β-carotene in a normal population of lactating women. Methodology to evaluate and protocol to accommodate the significant variation in carotenoids of human milk is also presented. Carotenoids present in the highest concentrations in breastmilk of these mothers were lycopene and β-carotene at 31.2 and 45.9 n m respectively, α-carotene and β-carotene concentrations in this population of mothers showed the greatest variation, ranging as much as 20-fold between individuals. The remaining carotenoids varied fourfold to sixfold across individuals. Within individuals, carotenoid concentrations varied from twofold to fivefold when measured on separate days. For an individual on a single day, breastmilk carotenoid concentrations vary as much as fourfold and are strongly correlated with lipid concentrations. For routine field collections, a collection protocol was developed that will approximate 24-hr collections of a population of mothers within 10%.